Heat exchanger

ABSTRACT

A heat exchanger is provided with: an air coolant line through which air coolant (AC) flows; a compressed air branching line through which compressed air flows; a plurality of heat exchange units for performing heat exchange between the air coolant and the compressed air, the heat exchange units being disposed side by side in a flow direction of the air coolant; a flow rate-adjusting valve for adjusting the flow rate of the compressed air flowing through the second heat exchange unit of the plurality of heat exchange units, the second heat exchange unit being positioned at a downstream side in the flow direction of the air coolant; temperature sensors for detecting the temperature of the compressed air; and a control unit configured to adjust the degree of opening of the flow rate-adjusting valve in accordance with the compressed air temperatures detected by the temperature sensors.

TECHNICAL FIELD

The present invention relates to a heat exchanger which performs heat exchange between a primary fluid and a secondary fluid.

BACKGROUND ART

In a case of cooling or heating a secondary fluid by performing heat exchange between a primary fluid and the secondary fluid, there is a heat exchanger configured by connecting an inlet header and an outlet header by a large number of heat exchanger tubes. In such a heat exchanger, when the secondary fluid supplied to the inlet header flows to the outlet header through the large number of heat exchanger tubes, the secondary fluid is cooled or heated by the primary fluid which comes into contact with the heat exchanger tubes.

For example, there is a heat exchanger having a configuration disclosed in the following PTL 1. The heat exchanger disclosed in PTL 1 is a heating or vaporizing device for heating or vaporizing a low-temperature fluid and makes a heat medium flow down along both faces of a heat exchange panel, thereby heating or vaporizing the low-temperature fluid which flows through heat exchanger tubes configuring the panel. Further, regulating valves are provided just before inlets of two headers or manifolds, and the regulating valves are operated so as to stop the supply of the low-temperature fluid to some of the heat exchanger panels according to variation in the supply amount of the low-temperature fluid and maintain the flow rate at the time of a steady load in the remaining heat exchanger panels.

Further, in a case of adjusting the temperature of the primary fluid by performing heat exchange between the primary fluid and the secondary fluid, it is conceivable to mix a part of the primary fluid with the primary fluid after heat exchange, without heat exchange. For example, a heat exchanger may be provided in a primary flow path, and a bypass flow path which bypasses the heat exchanger may be provided at the primary flow path. Then, the temperature of the primary fluid is adjusted by increasing or reducing the flow rate of the primary fluid flowing through the bypass flow path.

As such a heat exchanger, for example, there are heat exchangers disclosed in the following PTLs 2 and 3.

CITATION LIST Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 2009-052724

[PTL 2] Japanese Unexamined Patent Application Publication No. 2005-221180

[PTL 3] Japanese Unexamined Patent Application Publication No. 2005-226957

SUMMARY OF INVENTION Technical Problem

In the heat exchanger in which the inlet header and the outlet header are connected by a large number of heat exchanger tubes, heat exchange is performed between the primary fluid and the secondary fluid by making the primary fluid flow so as to cross the heat exchanger tube at right angles outside of each heat exchanger tube while making the secondary fluid flow in each heat exchanger tube. At this time, if the flow rate of the secondary fluid is reduced, the flow rate of the secondary fluid flowing to each heat exchanger tube is reduced, and therefore, in particular, in a heat exchanger tube which is disposed on the upstream side of the primary fluid, the secondary fluid enters a supercooled state or an overheated state. For this reason, also in the heat exchanger in which the inlet header and the outlet header are connected by a large number of heat exchanger tubes, it is desirable to be able to suppress supercooling or overheating of the secondary fluid by having a configuration in which it is possible to stop the supply of the low-temperature fluid to the heat exchange panels according to variation in the supply amount of the low-temperature fluid, as in the heating or vaporizing device disclosed in PTL 1.

Further, if the flow rate of the primary fluid flowing from the primary flow path to the bypass flow path is increased, the flow rate of the primary fluid flowing through the heat exchanger is reduced. Then, in the heat exchanger, the amount of heat exchange increases, and thus an overheated state or a supercooled state of the primary fluid is created at an outlet portion. In the heat exchanger, if the secondary fluid enters an overheated state or a supercooled state, a large thermal load acts on constituent members (for example, heat exchanger tubes) of the heat exchanger, and therefore, it is necessary to take measures against this in advance and an increase in the cost of the heat exchanger is caused. Further, if the primary fluid enters an overheated state or a supercooled state, there is a case where by-products may be produced, and there is a concern that these by-products may adversely affect the heat exchanger.

The present invention is for solving the above-described problems and has an object to provide a heat exchanger in which it is possible to suppress supercooling or overheating of a secondary fluid by suitably performing heat exchange even if the flow rate of a primary fluid varies.

Further, the present invention has an object to provide a heat exchanger in which it is possible to adjust the temperature of a primary fluid with a high degree of accuracy and it is possible to suppress overheating or supercooling of the primary fluid.

Solution to Problem

In order to achieve the above objects, according to an aspect of the present invention, there is provided a heat exchanger including: a primary flow path through which a primary fluid flows; a secondary flow path through which a secondary fluid flows within the primary flow path; a plurality of heat exchange units which perform heat exchange between the primary fluid and the secondary fluid and are provided side by side in a flow direction of the secondary fluid; and a flow rate-adjusting valve which adjusts a flow rate of the primary fluid flowing to the plurality of heat exchange units.

Therefore, the primary fluid flowing through the plurality of heat exchange units is cooled or heated by heat exchange with the secondary fluid. If the state of the primary fluid flowing through the plurality of heat exchange units varies, the degree of opening of the flow rate-adjusting valve is adjusted according to the state of the primary fluid, and therefore, the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid in the plurality of heat exchange units is adjusted. For this reason, the influence of the secondary fluid on each heat exchange unit becomes less and a rise to a higher temperature or a lowering to a lower temperature is suppressed. As a result, it is possible to suppress supercooling or superheating of the primary fluid by suitably performing heat exchange even if the state of the primary fluid varies.

Further, according to another aspect of the present invention, there is provided a heat exchanger including: a primary flow path through which a primary fluid flows; a secondary flow path through which a secondary fluid flows within the primary flow path; a plurality of heat exchange units which perform heat exchange between the primary fluid and the secondary fluid and are provided side by side in a flow direction of the secondary fluid; a flow rate-adjusting valve which adjusts a flow rate of the primary fluid flowing to the plurality of heat exchange units; a state detection sensor which detects a state of the primary fluid; and a control unit which adjusts a degree of opening of the flow rate-adjusting valve according to the state of the primary fluid detected by the state detection sensor.

Therefore, the primary fluid flowing through the plurality of heat exchange units is cooled or heated by heat exchange with the secondary fluid. If the state of the primary fluid flowing through the plurality of heat exchange units varies, the degree of opening of the flow rate-adjusting valve is adjusted according to the state of the primary fluid, and therefore, the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid in the plurality of heat exchange units is adjusted. For this reason, the influence of the secondary fluid on each heat exchange unit becomes less and a rise to a higher temperature or a lowering to a lower temperature is suppressed. As a result, it is possible to suppress supercooling or overheating of the secondary fluid by suitably performing heat exchange even if the state of the primary fluid varies.

In the heat exchanger according to the present invention, the plurality of heat exchange units have an individual inlet header provided at one end portion and a shared outlet header provided at the other end portion, the primary flow path is connected to the inlet header and the outlet header, and the flow rate-adjusting valve is provided in the primary flow path which is connected to the inlet header.

Therefore, a branching primary flow path is connected to the upstream side in the plurality of heat exchange units and the flow rate-adjusting valve is provided in the primary flow path which is connected to a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid, whereby the flow rate of the primary fluid flowing to the plurality of heat exchange units can be adjusted with a high degree of accuracy.

In the heat exchanger according to the present invention, the plurality of heat exchange units have a shared inlet header provided at one end portion and an individual outlet header provided at the other end portion, the primary flow path is connected to the inlet header and the outlet header, and the flow rate-adjusting valve is provided in the primary flow path which is connected to the outlet header.

Therefore, a branching primary flow path is connected to the downstream side in the plurality of heat exchange units and the flow rate-adjusting valve is provided in the primary flow path which is connected to a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid, whereby the flow rate of the primary fluid flowing to the plurality of heat exchange units can be adjusted with a high degree of accuracy.

In the heat exchanger according to the present invention, the state detection sensor is a temperature sensor which detects a temperature of the primary fluid in the side of outlets of the plurality of heat exchange units, and the control unit reduces the degree of opening of the flow rate-adjusting valve when a difference in temperature of the primary fluid in the side of outlets of the plurality of heat exchange units has become larger than a predetermined temperature difference set in advance.

Therefore, when a difference in temperature of the primary fluid flowing through the plurality of heat exchange units has become larger than the predetermined temperature difference, the degree of opening of the flow rate-adjusting valve is reduced, and therefore, the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid is reduced. For this reason, the influence of the secondary fluid on a heat exchange unit which is located on the upstream side in the flow direction of the secondary fluid becomes less, and it is possible to suppress supercooling or overheating of the primary fluid.

In the heat exchanger according to the present invention, the state detection sensor is a flow rate sensor which detects a flow rate of the primary fluid in the side of inlets of the plurality of heat exchange units, and the control unit reduces the degree of opening of the flow rate-adjusting valve when the flow rate of the primary fluid in the side of inlets of the plurality of heat exchange units has become smaller than a predetermined flow rate set in advance.

Therefore, when the flow rate of the primary fluid flowing through the plurality of heat exchange units has become smaller than the predetermined flow rate, the degree of opening of the flow rate-adjusting valve is reduced, and therefore, the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid is reduced. For this reason, the influence of the secondary fluid on a heat exchange unit which is located on the upstream side in the flow direction of the secondary fluid becomes less, and it is possible to suppress supercooling or overheating of the primary fluid.

In the heat exchanger according to the present invention, the state detection sensor is a pressure sensor which detects a pressure of the primary fluid in the side of inlets of the plurality of heat exchange units, and the control unit reduces the degree of opening of the flow rate-adjusting valve when the pressure of the primary fluid in the side of inlets of the plurality of heat exchange units has become larger than a predetermined pressure set in advance.

Therefore, when the pressure of the primary fluid flowing through the plurality of heat exchange units has become larger than the predetermined pressure, the degree of opening of the flow rate-adjusting valve is reduced, and therefore, the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid is reduced. For this reason, the influence of the secondary fluid on a heat exchange unit which is located on the upstream side in the flow direction of the secondary fluid becomes less, and it is possible to suppress supercooling or overheating of the primary fluid.

In the heat exchanger according to the present invention, a plurality of the flow rate-adjusting valves are provided to correspond to the plurality of heat exchange units, and the control unit adjusts the degrees of opening of the plurality of flow rate-adjusting valves such that the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in a flow direction of the secondary fluid in the plurality of heat exchange units is reduced according to the state of the primary fluid detected by the state detection sensor.

Therefore, the flow rate of the primary fluid flowing through the plurality of heat exchange units is adjusted, whereby the influence of the secondary fluid on each heat exchange unit becomes less and supercooling or overheating of the primary fluid can be suppressed with a high degree of accuracy.

Further, in order to achieve the above objects, according to still another aspect of the present invention, there is provided a heat exchanger including: a primary flow path through which a primary fluid flows; a secondary flow path through which a secondary fluid flows within the primary flow path; a plurality of heat exchange units which perform heat exchange between the primary fluid and the secondary fluid; a bypass flow path which bypasses at least one heat exchange unit among the plurality of heat exchange units; a flow rate-adjusting valve which adjusts a flow rate of the primary fluid flowing through the bypass flow path; a temperature sensor which measures a temperature of the primary fluid in the side of outlets of the plurality of heat exchange units; and a control unit which adjusts a degree of opening of the flow rate-adjusting valve according to the temperature of the primary fluid detected by the temperature sensor.

Therefore, the degree of opening of the flow rate-adjusting valve is adjusted according to the temperature of the primary fluid in the outlet side of the heat exchange unit, and therefore, the flow rate of the primary fluid which bypasses at least one heat exchange unit among the plurality of heat exchange units is adjusted. At this time, the primary fluid bypasses at least one heat exchange unit, and therefore, even if the flow rate of the primary fluid which has passed through this heat exchange unit is temporarily reduced, a rise to a higher temperature or a lowering to a lower temperature is suppressed. As a result, it is possible to adjust the temperature of the primary fluid with a high degree of accuracy and it is possible to suppress overheating or supercooling of the primary fluid.

In the heat exchanger according to the present invention, the plurality of heat exchange units have a first heat exchange unit and a second heat exchange unit connected in series, and the bypass flow path is connected, at one end portion, to an inlet of the first heat exchange unit and connected, at the other end portion, to a connection section between the first heat exchange unit and the second heat exchange unit.

Therefore, the primary fluid passing through the bypass flow path is supplied to the connection section between the first heat exchange unit and the second heat exchange unit, whereby the primary fluid subjected to heat exchange in the first heat exchange unit is mixed with the primary fluid which has passed through the bypass flow path, and a rise to a higher temperature or a lowering to a lower temperature of the primary fluid in the second heat exchange unit is suppressed, and thus it is possible to suppress overheating or supercooling of the primary fluid.

In the heat exchanger according to the present invention, the first heat exchange unit and the second heat exchange unit are disposed in parallel, an inlet portion of the first heat exchange unit and an outlet portion of the second heat exchange unit are disposed at one end portion, and the connection section is disposed at the other end portion.

Therefore, due to a configuration made so as to efficiently circulate the primary fluid by disposing the first heat exchange unit and the second heat exchange unit in parallel, it is possible to attain a reduction in the size of the device.

In the heat exchanger according to the present invention, the connection section is a header to which a downstream-side end portion in the first heat exchange unit and an upstream-side end portion in the second heat exchange unit are connected.

Therefore, the connection section is made to be a header, whereby it is possible to easily connect the first heat exchange unit and the second heat exchange unit, and it is possible to suitably mix the primary fluid which has passed through the heat exchange unit and the primary fluid which has passed through the bypass flow path.

In the heat exchanger according to the present invention, the connection section is a connection pipe which connects a downstream-side end portion in the first heat exchange unit to an upstream-side end portion in the second heat exchange unit.

Therefore, the connection section is made to be a connection pipe, whereby it is possible to compactly connect the first heat exchange unit to the second heat exchange unit and it is possible to simplify the structure.

In the heat exchanger according to the present invention, the flow rate-adjusting valve is provided in the bypass flow path.

Therefore, it is possible to simplify the structure and it is possible to reduce the manufacturing cost.

In the heat exchanger according to the present invention, the flow rate-adjusting valve is a three-way valve which is provided in a branch section between the primary flow path and the bypass flow path.

Therefore, the flow rate of the primary fluid flowing to the bypass flow path can be adjusted with a high degree of accuracy.

Advantageous Effects of Invention

According to the heat exchanger according to the present invention, the flow rate of the primary fluid flowing through a heat exchange unit which is located on the downstream side in the flow direction of the secondary fluid is adjusted according to the state of the primary fluid, and therefore, it is possible to suppress supercooling or overheating of the primary fluid by suitably performing heat exchange even if the state of the primary fluid varies.

Further, according to the heat exchanger according to the present invention, the plurality of heat exchange units performing heat exchange between the primary fluid and the secondary fluid are provided, the bypass flow path which bypasses at least one heat exchange unit among the plurality of heat exchange units is provided, and the flow rate of the primary fluid flowing through the bypass flow path is adjusted according to the temperature of the primary fluid in the side of outlets of the plurality of heat exchange units. Therefore, it is possible to adjust the temperature of the primary fluid with a high degree of accuracy and it is possible to suppress overheating or supercooling of the primary fluid.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic configuration diagram showing a gas turbine.

FIG. 2 is a schematic diagram showing a heat exchange device.

FIG. 3 is a schematic configuration diagram of a heat exchanger of a first embodiment.

FIG. 4 is a schematic configuration diagram of a heat exchanger showing a modification example of the first embodiment.

FIG. 5 is a schematic diagram showing an operation of the heat exchanger of the first embodiment.

FIG. 6 is a schematic configuration diagram of a heat exchanger of a second embodiment.

FIG. 7 is a schematic configuration diagram of a heat exchanger showing a modification example of the second embodiment.

FIG. 8 is a schematic configuration diagram of a heat exchanger of a third embodiment.

FIG. 9 is a schematic configuration diagram of a heat exchanger showing a modification example of the third embodiment.

FIG. 10 is a schematic configuration diagram of a heat exchanger of a fourth embodiment.

FIG. 11 is a schematic configuration diagram showing a gas turbine.

FIG. 12 is a schematic diagram showing a heat exchange device.

FIG. 13 is a schematic configuration diagram of a heat exchanger of a fifth embodiment.

FIG. 14 is a schematic configuration diagram of a heat exchanger showing a modification example of the fifth embodiment.

FIG. 15 is a schematic diagram showing an operation of a heat exchanger of the related art.

FIG. 16 is a schematic diagram showing an operation of the heat exchanger of the fifth embodiment.

FIG. 17 is a schematic configuration diagram of a heat exchanger of a sixth embodiment.

FIG. 18 is a schematic configuration diagram of a heat exchanger showing a modification example of the sixth embodiment.

FIG. 19 is a schematic configuration diagram of a heat exchanger of a seventh embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments of a heat exchanger according to the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited by the embodiments, and in a case where there are a plurality of embodiments, the present invention also includes configurations made by combining the respective embodiments.

First Embodiment

FIG. 1 is a schematic configuration diagram showing a gas turbine.

In the first embodiment, as shown in FIG. 1, a gas turbine 10 is configured to include a compressor 11, a combustor 12, and a turbine 13. A power generator 14 is connected to the gas turbine 10, and thus the gas turbine 10 is made to be able to generate electric power.

The compressor 11 and the turbine 13 are connected so as to be able to integrally rotate by a rotary shaft 21. The compressor 11 compresses air A taken in from an air intake line 22. The combustor 12 mixes compressed air A1 supplied from the compressor 11 through a compressed air supply line 23 and fuel gas L supplied from a fuel gas supply line 24 and burns the mixture. The turbine 13 is rotated by combustion gas G supplied from the combustor 12 through a combustion gas supply line 25.

Further, the gas turbine 10 is provided with a heat exchange device 26 which performs heat exchange between compressed air A2 which is a part of the compressed air A1 compressed in the compressor 11, an air coolant AC taken in from the outside, and the fuel gas L. The heat exchange device 26 is provided at a position at which the fuel gas supply line 24, a compressed air branching line which supplies the compressed air A2, and an air coolant line 28 are gathered together. The heat exchange device 26 cools the compressed air A2 by the air coolant AC and heats the fuel gas L by heated air AH having a raised temperature. The cooled compressed air A2 is supplied through a casing of the turbine 13, thereby cooling blades or the like as an air coolant.

The power generator 14 is connected so as to be able to integrally rotate by a rotary shaft 29 coaxial with the compressor 11 and can generate electric power by the rotation of the turbine 13.

FIG. 2 is a schematic diagram showing the heat exchange device.

In the heat exchange device 26, as shown in FIG. 2, two heat exchangers 32 and 33 are disposed in a housing 31. An air intake 34 is provided at a lower portion of the housing 31, and an intake fan 35 is provided in the air intake 34. On the other hand, an air outlet 36 is provided at an upper portion of the housing 31.

The first heat exchanger 32 performs heat exchange between the compressed air A2 compressed in the compressor 11 and the air coolant AC taken in from the outside. That is, the first heat exchanger 32 cools the compressed air A2 by the air coolant AC which is at normal temperature. Further, the second heat exchanger 33 performs heat exchange between the heated air AH heated to a high temperature by cooling the compressed air A2, and the fuel gas L. That is, the air coolant AC becomes the high-temperature heated air AH by cooling the compressed air A2, and the second heat exchanger 33 heats the fuel gas L by the heated air AH.

Hereinafter, the first heat exchanger as a heat exchanger of the first embodiment will be described. FIG. 3 is a schematic configuration diagram of the heat exchanger of the first embodiment.

The first heat exchanger 32 of the first embodiment has the compressed air branching line 27 as a primary flow path, the air coolant line 28 as a secondary flow path, a plurality of (in this embodiment, two) first and second heat exchange units 41 and 42, and a flow rate-adjusting valve 43, as shown in FIG. 3. Here, a primary fluid is the compressed air A2, and a secondary fluid is the air coolant AC.

The compressed air branching line 27 and the air coolant line 28 are disposed so as to be substantially orthogonal to each other. Further, the first heat exchange unit 41 and the second heat exchange unit 42 are provided side by side in a flow direction of the air coolant AC, and the second heat exchange unit 42 is disposed on the downstream side with respect to the first heat exchange unit 41 in the flow direction of the air coolant AC.

The first heat exchange unit 41 and the second heat exchange unit 42 are provided in the compressed air branching line 27, perform heat exchange between the compressed air A2 and the air coolant AC, are provided adjacent to each other in parallel, and are disposed in parallel to each other. An individual inlet header 51 is provided at one end portion of the first heat exchange unit 41, and an individual inlet header 52 is provided at one end portion of the second heat exchange unit 42. Further, a shared outlet header 53 is provided at the other end portions of the first heat exchange unit 41 and the second heat exchange unit 42. A first branching flow path 54 a and a second branching flow path 54 b as primary fluid supply paths are branched from the compressed air branching line 27, the first branching flow path 54 a is connected to a nozzle 55 of the inlet header 51 in the first heat exchange unit 41, and the second branching flow path 54 b is connected to a nozzle 56 of the inlet header in the second heat exchange unit 42. Further, a gathering flow path 54 c as a primary fluid discharge path is provided in the compressed air branching line 27 and connected to a nozzle 57 of the outlet header 53.

The flow rate-adjusting valve 43 is provided in the second branching flow path 54 b and adjusts the flow rate of the compressed air A2 flowing through the second branching flow path 54 b.

The first heat exchanger 32 is usually operated with the degree of opening of the flow rate-adjusting valve 43 as 100% (fully opened). That is, the flow rates of the compressed air A2 which is supplied from the compressed air branching line 27 to the first heat exchange unit 41 and the second heat exchange unit 42 through the first branching flow path 54 a and the second branching flow path 54 b are set to be equal to each other. The compressed air A2 is cooled by heat exchange with the air coolant AC when flowing through the first heat exchange unit 41 and the second heat exchange unit 42, and then discharged.

If the flow rate of the compressed air A2 flowing through the compressed air branching line 27 is reduced, the degree of opening of the flow rate-adjusting valve 43 is reduced. Then, while the flow rate of the compressed air A2 which is supplied to the second heat exchange unit 42 through the second branching flow path 54 b is reduced, the flow rate of the compressed air A2 which is supplied to the first heat exchange unit 41 through the first branching flow path 54 a relatively increases. If the flow rate of the compressed air A2 in the first heat exchange unit 41 increases, when heat exchange between the air coolant AC and the compressed air A2 is performed, a thermal load of the first heat exchange unit 41 becomes higher than a thermal load of the second heat exchange unit 42, whereby supercooling is suppressed.

In addition, the configuration of the first heat exchanger 32 is not limited to the above-described configuration. FIG. 4 is a schematic configuration diagram of a heat exchanger showing a modification example of the first embodiment.

As shown in FIG. 4, a first heat exchanger 32A showing the modification example of the first embodiment has the compressed air branching line 27, the air coolant line 28, the first heat exchange unit 41, the second heat exchange unit 42, and the flow rate-adjusting valve 43.

A shared inlet header 61 is provided at end portions on one side of the first heat exchange unit 41 and the second heat exchange unit 42. Further, an individual outlet header 62 is provided at the other end portion of the first heat exchange unit 41, and an individual outlet header 63 is provided at the other end portion of the second heat exchange unit 42. A supply flow path 64 a as a primary fluid supply path is provided in the compressed air branching line 27 and connected to a nozzle 65 of the inlet header 61. Further, a first branching flow path 64 b and a second branching flow path 64 c as primary fluid discharge paths are branched from the compressed air branching line 27, the first branching flow path 64 b is connected to a nozzle 66 of the outlet header 62 of the first heat exchange unit 41, and the second branching flow path 64 c is connected to a nozzle 67 of the outlet header 63 of the second heat exchange unit 42.

The flow rate-adjusting valve 43 is provided in the second branching flow path 64 c and adjusts the flow rate of the compressed air A2 flowing through the second branching flow path 64 c.

The first heat exchanger 32A is usually operated with the degree of opening of the flow rate-adjusting valve 43 as 100% (fully opened). That is, the flow rates of the compressed air A2 which is supplied from the compressed air branching line 27 to the first heat exchange unit 41 and the second heat exchange unit 42 through the supply flow path 64 a are set to be equal to each other. The compressed air A2 is cooled by heat exchange with the air coolant AC when flowing through the first heat exchange unit 41 and the second heat exchange unit 42, and then discharged.

If the flow rate of the compressed air A2 flowing through the compressed air branching line 27 is reduced, the degree of opening of the flow rate-adjusting valve 43 is reduced. Then, while the flow rate of the compressed air A2 which is discharged from the second heat exchange unit 42 through the second branching flow path 64 c is reduced, the flow rate of the compressed air A2 which is discharged from the first heat exchange unit 41 through the first branching flow path 64 b relatively increases. If the flow rate of the compressed air A2 in the first heat exchange unit 41 increases, when heat exchange between the air coolant AC and the compressed air A2 is performed, a thermal load of the first heat exchange unit 41 becomes higher than a thermal load of the second heat exchange unit 42, whereby supercooling is suppressed.

Here, the operations of the first heat exchanger 32 will be described. FIG. 5 is a schematic diagram showing the operation of the heat exchanger of the first embodiment.

As shown in FIG. 5, when the degree of opening of the flow rate-adjusting valve 43 is full open, the flow rates of the compressed air A2 which is supplied from the respective inlet headers 51 and 52 to the respective heat exchange units 41 and 42 become equal to each other. For this reason, at this time, if the air coolant AC acts on the respective heat exchange units 41 and 42, as shown by a dot-and-dash line, the air coolant AC which is at an atmospheric temperature Ta at an inlet portion C1 rises in temperature by cooling the compressed air A2, thereby reaching a temperature Tb at an outlet portion C3, and is discharged. For this reason, the compressed air A2 is cooled to a predetermined temperature.

On the other hand, if the flow rate of the compressed air A2 flowing through the compressed air branching line 27 is reduced, the degree of opening of the flow rate-adjusting valve 43 is reduced (made to be, for example, fully closed), whereby the flow rate of the compressed air A2 which is supplied from the inlet header to the first heat exchange unit 41 increases with respect to the flow rate of the compressed air A2 which is supplied from the inlet header 52 to the second heat exchange unit 42. For this reason, at this time, if the air coolant AC acts on the respective heat exchange units 41 and 42, as shown by a solid line, the air coolant AC which is at the atmospheric temperature Ta at the inlet portion C1 rises in temperature by cooling the compressed air A2, thereby reaching the temperature Tb at C2 between the first heat exchange unit 41 and the second heat exchange unit 42, and is discharged. For this reason, the compressed air A2 is cooled to a predetermined temperature.

That is, the flow rate-adjusting valve 43 is fully closed, whereby the total amount of the compressed air A2 flowing through the compressed air branching line 27 is supplied to the first heat exchange unit 41, and therefore, the flow rate of the compressed air A2 flowing through the first heat exchange unit 41 per unit time increases and the flow velocity of the compressed air A2 becomes higher. For this reason, while the compressed air A2 passes through the first heat exchange unit 41, more heat thereof is absorbed by the air coolant AC, and thus the air coolant AC reaches the temperature Tb at C2 between the first heat exchange unit 41 and the second heat exchange unit 42. For this reason, supercooling in the first heat exchange unit 41 is suppressed. On the other hand, in the second heat exchange unit 42, although the compressed air A2 does not flow therethrough, the compressed air A2 having a raised temperature acts thereon, and therefore, supercoiling here is also suppressed.

In this manner, the heat exchanger of the first embodiment is provided with the compressed air branching line 27 as a primary flow path through which the compressed air A2 as a primary fluid flows, the air coolant line 28 as a secondary flow path through which the air coolant AC as a secondary fluid flows, the first and second heat exchange units 41 and 42 as a plurality of heat exchange units which perform heat exchange between the air coolant AC and the compressed air A2 and are provided side by side in a flow direction of the air coolant AC, and the flow rate-adjusting valve 43 which adjusts the flow rate of the compressed air A2 flowing through the second heat exchange unit 42 which is located on the downstream side in the flow direction of the air coolant AC in the plurality of heat exchange units 41 and 42.

Therefore, the compressed air A2 flowing through the plurality of heat exchange units 41 and 42 is cooled by heat exchange with the air coolant AC. If the flow rates of the compressed air A2 flowing through the plurality of heat exchange units 41 and 42 vary, the degree of opening of the flow rate-adjusting valve 43 is adjusted according to the flow rate of the compressed air A2, and therefore, the flow rate of the compressed air A2 flowing through the second heat exchange unit 42 which is located on the downstream side in the flow direction of the air coolant AC in the plurality of heat exchange units 41 and 42 is adjusted. For this reason, the influence of the air coolant AC on the respective heat exchange units 41 and 42 is less, and thus a rise to a higher temperature or a lowering to a lower temperature is suppressed. As a result, it is possible to suppress supercooling of the compressed air A2 by suitably performing heat exchange even if the flow rate of the compressed air A2 varies.

Second Embodiment

FIG. 6 is a schematic configuration diagram of a heat exchanger of a second embodiment, and FIG. 7 is a schematic configuration diagram of a heat exchanger showing a modification example of the second embodiment. In addition, members having the same functions as those in the above-described embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

In the second embodiment, as shown in FIG. 6, a first heat exchanger 32B has the compressed air branching line 27, the air coolant line 28, the first heat exchange unit 41, the second heat exchange unit 42, the flow rate-adjusting valve 43, first and second temperature sensors 71 and 72 as state detection sensors, and a control unit 73.

The first temperature sensor 71 and the second temperature sensor 72 are provided at the outlet header 53. The first temperature sensor 71 detects the temperature (the state) of the compressed air A2 discharged from the first heat exchange unit 41 to the outlet header 53 and outputs the detection result to the control unit 73. The second temperature sensor 72 detects the temperature (the state) of the compressed air A2 discharged from the second heat exchange unit 42 to the outlet header 53 and outputs the detection result to the control unit 73. The control unit 73 adjusts the degree of opening of the flow rate-adjusting valve 43 according to the temperatures of the compressed air A2 detected by the first temperature sensor and the second temperature sensor 72. That is, the control unit 73 reduces the degree of opening of the flow rate-adjusting valve 43 when a difference between the temperatures of the compressed air A2 detected by the respective temperature sensors 71 and 72 has become larger than a predetermined temperature difference set in advance. Further, the control unit 73 adjusts the degree of opening of the flow rate-adjusting valve 43 such that the temperatures of the compressed air A2 detected by the first temperature sensor 71 and the second temperature sensor are within the predetermined temperature difference.

The first heat exchanger 32B is usually operated with the degree of opening of the flow rate-adjusting valve 43 as 100% (fully opened). That is, the flow rates of the compressed air A2 which is supplied from the compressed air branching line 27 to the first heat exchange unit 41 and the second heat exchange unit 42 through the first branching flow path 54 a and the second branching flow path 54 b are set to be equal to each other. The compressed air A2 is cooled by heat exchange with the air coolant AC when flowing through the first heat exchange unit 41 and the second heat exchange unit 42, and then discharged.

The control unit 73 determines that the flow rate of the compressed air A2 flowing through the compressed air branching line 27 has been reduced, if the deviation between the temperature of the compressed air A2 which is discharged from the first heat exchange unit 41 and the temperature of the compressed air A2 which is discharged from the second heat exchange unit 42 becomes larger than a predetermined temperature difference. At this time, the control unit 73 reduces the degree of opening of the flow rate-adjusting valve 43, thereby adjusting the degree of opening of the flow rate-adjusting valve 43 such that the temperatures of the compressed air A2 detected by the first temperature sensor 71 and the second temperature sensor 72 are within the predetermined temperature difference. Then, while the flow rate of the compressed air A2 which is supplied to the second heat exchange unit 42 through the second branching flow path 54 b is reduced, the flow rate of the compressed air A2 which is supplied to the first heat exchange unit 41 through the first branching flow path 54 a relatively increases. If the flow rate of the compressed air A2 in the first heat exchange unit 41 increases, when heat exchange between the air coolant AC and the compressed air A2 is performed, a thermal load of the first heat exchange unit 41 becomes higher than a thermal load of the second heat exchange unit 42, whereby supercooling is suppressed.

In addition, the configuration of the first heat exchanger 32B is not limited to the above-described configuration. As shown in FIG. 7, in a first heat exchanger 32C, the first temperature sensor 71 is provided in the first branching flow path 64 b connected to the outlet header 62 in the first heat exchange unit 41, detects the temperature of the compressed air A2 discharged from the first heat exchange unit 41, and outputs the detection result to the control unit 73. The second temperature sensor 72 is provided in the second branching flow path 64 c connected to the outlet header 63 in the second heat exchange unit 42, detects the temperature of the compressed air A2 discharged from the second heat exchange unit 42, and outputs the detection result to the control unit 73. The control unit 73 adjusts the degree of opening of the flow rate-adjusting valve 43 according to the temperatures of the compressed air A2 detected by the first temperature sensor 71 and the second temperature sensor 72. That is, the control unit reduces the degree of opening of the flow rate-adjusting valve 43 when a difference between the temperatures of the compressed air A2 detected by the respective temperature sensors 71 and 72 has become larger than a predetermined temperature difference set in advance. Further, the control unit 73 adjusts the degree of opening of the flow rate-adjusting valve 43 such that the temperatures of the compressed air A2 detected by the first temperature sensor 71 and the second temperature sensor 72 are within the predetermined temperature difference.

In this manner, the heat exchanger of the second embodiment is provided with the air coolant line 28 through which the air coolant AC flows, the compressed air branching line 27 through which the compressed air A2 flows, the plurality of heat exchange units 41 and 42 which perform heat exchange between the air coolant AC and the compressed air A2 and are provided side by side in the flow direction of the air coolant AC, the flow rate-adjusting valve 43 which adjusts the flow rate of the compressed air A2 flowing through the second heat exchange unit 42 which is located on the downstream side in the flow direction of the air coolant AC in the plurality of heat exchange units 41 and 42, the temperature sensors 71 and 72 which detect the temperature of the compressed air A2, and the control unit 73 which adjusts the degree of opening of the flow rate-adjusting valve 43 according to the temperatures of the compressed air A2 detected by the temperature sensors 71 and 72.

Therefore, the compressed air A2 flowing through the plurality of heat exchange units 41 and 42 is cooled by heat exchange with the air coolant AC. If the temperatures of the compressed air A2 flowing through the plurality of heat exchange units 41 and 42 vary, the degree of opening of the flow rate-adjusting valve 43 is adjusted according to the temperature of the compressed air A2, and therefore, the flow rate of the compressed air A2 flowing through the second heat exchange unit 42 which is located on the downstream side in the flow direction of the air coolant AC in the plurality of heat exchange units 41 and 42 is adjusted. For this reason, the influence of the air coolant AC on the respective heat exchange units 41 and 42 is less, and thus a rise to a higher temperature or a lowering to a lower temperature is suppressed. As a result, it is possible to suppress supercooling of the compressed air A2 by suitably performing heat exchange even if the flow rate of the compressed air A2 varies.

In the heat exchanger of the second embodiment, the control unit 73 reduces the degree of opening of the flow rate-adjusting valve 43 when a difference between the temperatures of the compressed air A2 in the side of outlets of the plurality of heat exchange units 41 and 42 has become larger than a predetermined temperature difference set in advance, thereby adjusting the degree of opening of the flow rate-adjusting valve 43 such that the difference in temperature of the compressed air A2 is within the predetermined temperature difference. If the degree of opening of the flow rate-adjusting valve 43 is reduced, the flow rate of the compressed air A2 flowing through the second heat exchange unit 42 which is located on the downstream side in the flow direction of the air coolant AC is reduced. For this reason, the influence of the compressed air A2 on the first heat exchange unit 41 which is located on the upstream side in the flow direction of the air coolant AC becomes less, and thus it is possible to suppress supercooling of the compressed air A2.

Further, supercooling of the compressed air A2 is suppressed, whereby a large thermal load does not act on constituent members (for example, heat exchanger tubes or the like) of the heat exchange units 41 and 42, and an increase in plate thickness, or the like is not required, and thus it is possible to suppress an increase in manufacturing cost. Further, since supercooling of the compressed air A2 is suppressed, generation of drainage in the second heat exchange unit 42 is suppressed, and thus it is possible to prevent generation of rust due to the drainage.

In the first heat exchanger 32B, the flow rate-adjusting valve 43 is provided in the second branching flow path 54 b which is connected to the inlet header 52 of the second heat exchange unit 42. Further, in the first heat exchanger 32C, the flow rate-adjusting valve 43 is provided in the second branching flow path 64 c which is connected to the outlet header 63 of the second heat exchange unit 42. Therefore, the flow rates of the compressed air A2 flowing through the plurality of heat exchange units 41 and 42 can be adjusted with a high degree of accuracy.

Third Embodiment

FIG. 8 is a schematic configuration diagram of a heat exchanger of a third embodiment, and FIG. 9 is a schematic configuration diagram of a heat exchanger showing a modification example of the third embodiment. In addition, members having the same functions as those in the above-described embodiments are denoted by the same reference numerals and detailed description thereof is omitted.

In the third embodiment, as shown in FIG. 8, a first heat exchanger 32D has the compressed air branching line 27, the air coolant line 28, the first heat exchange unit 41, the second heat exchange unit 42, the flow rate-adjusting valve 43, a flow rate sensor 81 as a state detection sensor, and the control unit 73.

The flow rate sensor 81 is provided in the compressed air branching line 27. The flow rate sensor 81 detects the flow rate (the state) of the compressed air A2 flowing through the compressed air branching line 27 and outputs the detection result to the control unit 73. The control unit 73 adjusts the degree of opening of the flow rate-adjusting valve 43 according to the flow rate of the compressed air A2 detected by the flow rate sensor 81. That is, the control unit 73 reduces the degree of opening of the flow rate-adjusting valve 43 when the flow rate of the compressed air A2 detected by the flow rate sensor 81 has become smaller than a predetermined flow rate set in advance.

The first heat exchanger 32D is usually operated with the degree of opening of the flow rate-adjusting valve 43 as 100% (fully opened). That is, the flow rates of the compressed air A2 which is supplied from the compressed air branching line 27 to the first heat exchange unit 41 and the second heat exchange unit 42 through the first branching flow path 54 a and the second branching flow path 54 b are set to be equal to each other. The compressed air A2 is cooled by heat exchange with the air coolant AC when flowing through the first heat exchange unit 41 and the second heat exchange unit 42, and then discharged.

If the flow rate of the compressed air A2 which is supplied to the first heat exchange unit 41 becomes smaller than a predetermined flow rate, the control unit reduces the degree of opening of the flow rate-adjusting valve 43. Then, while the flow rate of the compressed air A2 which is supplied to the second heat exchange unit 42 through the second branching flow path 54 b is reduced, the flow rate of the compressed air A2 which is supplied to the first heat exchange unit 41 through the first branching flow path 54 a relatively increases. If the flow rate of the compressed air A2 in the first heat exchange unit 41 increases, when heat exchange between the air coolant AC and the compressed air A2 is performed, a thermal load of the first heat exchange unit 41 becomes higher than a thermal load of the second heat exchange unit 42, whereby supercooling is suppressed.

In addition, the configuration of the first heat exchanger 32D is not limited to the above-described configuration. As shown in FIG. 9, in a first heat exchanger 32E, the flow rate sensor 81 is provided in the compressed air branching line 27, detects the flow rate of the compressed air A2 which is supplied to the respective heat exchange units 41 and 42, and outputs the detection result to the control unit 73. The control unit 73 adjusts the degree of opening of the flow rate-adjusting valve 43 according to the flow rate of the compressed air A2 detected by the flow rate sensor 81. That is, the control unit 73 reduces the degree of opening of the flow rate-adjusting valve 43 when the flow rate of the compressed air A2 detected by the flow rate sensor 81 has become smaller than a predetermined flow rate set in advance.

In this manner, the heat exchanger of the third embodiment is provided with the flow rate sensor 81 which detects the flow rate of the compressed air A2, and the control unit 73 which reduces the degree of opening of the flow rate-adjusting valve 43 when the flow rate of the compressed air A2 detected by the flow rate sensor 81 has become smaller than a predetermined flow rate set in advance.

Therefore, when the flow rate of the compressed air A2 flowing through the plurality of heat exchange units 41 and 42 has become smaller than the predetermined flow rate, the degree of opening of the flow rate-adjusting valve 43 is reduced, and therefore, the flow rate of the secondary fluid flowing through the second heat exchange unit 42 is reduced. For this reason, the influence of the air coolant AC on the first heat exchange unit 41 becomes less, and thus it is possible to suppress supercooling of the compressed air A2.

In addition, in the third embodiment, a configuration is made such that the flow rate sensor 81 is provided in the compressed air branching line 27, thereby detecting the flow rate (the state) of the compressed air A2 flowing through the compressed air branching line 27. However, there is no limitation to this configuration. For example, a configuration may be made such that a pressure sensor is provided in the compressed air branching line 27, thereby detecting the pressure (the state) of the compressed air A2 flowing through the compressed air branching line 27. Then, the control unit reduces the degree of opening of the flow rate-adjusting valve 43 when the pressure of the compressed air A2 flowing through the compressed air branching line 27 detected by the pressure sensor has become larger than a predetermined pressure set in advance. Also in this case, it is possible to suppress supercooling of the compressed air A2.

Fourth Embodiment

FIG. 10 is a schematic configuration diagram of a heat exchanger of a fourth embodiment. In addition, members having the same functions as those in the above-described embodiments are denoted by the same reference numerals and detailed description thereof is omitted.

In the fourth embodiment, as shown in FIG. 10, a first heat exchanger 90 has the compressed air branching line 27, the air coolant line 28, four heat exchange units 91, 92, 93, and 94, flow rate-adjusting valves 95, 96, 97, and 98, a flow rate sensor (a state detection sensor) 99, and a control unit 100.

An inlet header 101 is provided at one end portion of the first heat exchange unit 91, an inlet header 102 is provided at one end portion of the second heat exchange unit 92, an inlet header 103 is provided at one end portion of the third heat exchange unit 93, and an inlet header 104 is provided at one end portion of the fourth heat exchange unit 94, and an outlet header 105 is provided at the other end portions of the respective heat exchange units 91, 92, 93, and 94. A first branching flow path 105 a, a second branching flow path 105 b, a third branching flow path 105 c, and a fourth branching flow path 105 d as primary fluid supply paths are branched from the compressed air branching line 27 and respectively connected to the inlet headers 101, 102, 103, and 104. Further, a gathering flow path 105 e as a primary fluid discharge path is provided at the compressed air branching line 27 and connected to the outlet header 105.

The flow rate-adjusting valves 95, 96, 97, and 98 are respectively provided in the branching flow paths 105 a, 105 b, 105 c, and 105 d and adjust the flow rates of the compressed air A2 flowing through the branching flow paths 105 a, 105 b, 105 c, and 105 d. The flow rate sensor 99 is provided in the compressed air branching line 27, detects the flow rate (the state) of the compressed air A2 flowing through the compressed air branching line 27, and outputs the detection result to the control unit 100. The control unit 100 adjusts the degrees of opening of the flow rate-adjusting valves 95, 96, 97, and 98 according to the flow rate of the compressed air A2 detected by the flow rate sensor 99. That is, the control unit 100 reduces the degrees of opening of the flow rate-adjusting valves 95, 96, 97, and 98 when the flow rate of the compressed air A2 detected by the flow rate sensor 99 has become smaller than a predetermined flow rate set in advance.

If the flow rate of the compressed air A2 which is supplied to the first heat exchange unit 91 becomes smaller than the predetermined flow rate, the control unit 100 adjusts the degrees of opening of the flow rate-adjusting valves 95, 96, 97, and 98, thereby performing adjustment such that the flow rate becomes smaller in the heat exchange units 92, 93, and 94 as they are further on the downstream side in the flow direction of the air coolant AC. For this reason, when heat exchange between the air coolant AC and the compressed air A2 is performed, a thermal load becomes higher toward the first heat exchange unit 91 side, whereby supercooling is suppressed.

In addition, in the fourth embodiment, the flow rate sensor 99 is applied as a state detection sensor. However, a temperature sensor or a pressure sensor is also acceptable.

In this manner, in the heat exchanger of the fourth embodiment, the plurality of flow rate-adjusting valves 95, 96, 97, and 98 are provided to correspond to the plurality of heat exchange units 91, 92, 93, and 94, and the control unit 100 adjusts the flow rates of the compressed air A2 flowing through the respective heat exchange units 91, 92, 93, and 94 according to the flow rate of the compressed air A2 detected by the flow rate sensor 99.

Therefore, the flow rates of the compressed air A2 flowing through the plurality of heat exchange units 91, 92, 93, and 94 are adjusted, whereby the influence of the air coolant AC on the respective heat exchange units 91, 92, 93, and 94 becomes less, and thus it is possible to suppress supercooling of the compressed air A2 with a high degree of accuracy.

In addition, in the embodiments described above, each of the heat exchange units 41, 42, 91, 92, 93, and 94 is configured with a heat exchanger tube which is a straight tube. However, the heat exchange unit may be configured with a U-shaped heat exchanger tube.

Further, in the embodiments described above, the heat exchanger according to the present invention is applied to the gas turbine 10 and cools the compressed air (a primary fluid) A2 by the air coolant (a secondary fluid) AC. However, there is no limitation to this configuration. That is, the heat exchanger according to the present invention can also be applied to another part in the gas turbine 10, or fields (for example, a boiler or the like) other than the gas turbine 10.

Further, in the embodiments described above, the heat exchanger which cools the primary fluid by the secondary fluid is adopted. However, a heat exchanger which heats the primary fluid by the secondary fluid may be adopted, and in this case, it is possible to suppress overheating due to the heat exchanger.

Fifth Embodiment

FIG. 11 is a schematic configuration diagram showing a gas turbine.

In a fifth embodiment, as shown in FIG. 11, the gas turbine 10 is configured to include the compressor 11, the combustor 12, and the turbine 13. The power generator 14 is connected to the gas turbine 10, and thus the gas turbine 10 is made to be able to generate electric power.

The compressor 11 and the turbine 13 are connected so as to be able to integrally rotate by a rotary shaft 21. The compressor 11 compresses the air A taken in from an air intake line 22. The combustor 12 mixes the compressed air A1 supplied from the compressor 11 through a compressed air supply line 23 and the fuel gas L supplied from a fuel gas supply line 24 and burns the mixture. The turbine 13 is rotated by the combustion gas G supplied from the combustor 12 through a combustion gas supply line 25.

Further, the gas turbine 10 is provided with a heat exchange device 26 which performs heat exchange between the compressed air A2 which is a part of the compressed air A1 compressed in the compressor 11, the air coolant AC taken in from the outside, and the fuel gas L. The heat exchange device 26 is provided at a position at which the fuel gas supply line 24, a compressed air branching line which supplies the compressed air A2, and an air coolant line 28 are gathered together. The heat exchange device 26 cools the compressed air A2 by the air coolant AC and heats the fuel gas L by the heated air AH having a raised temperature. The cooled compressed air A2 is supplied through a casing of the turbine 13, thereby cooling blades or the like as an air coolant.

The power generator 14 is connected so as to be able to integrally rotate by a rotary shaft 29 coaxial with the compressor 11 and can generate electric power by the rotation of the turbine 13.

FIG. 12 is a schematic diagram showing the heat exchange device.

In the heat exchange device 26, as shown in FIG. 12, two heat exchangers 132 and 133 are disposed in a housing 131. An air intake 134 is provided at a lower portion of the housing 131, and an intake fan 135 is provided in the air intake 134. On the other hand, an air outlet 136 is provided at an upper portion of the housing 131.

The first heat exchanger 132 performs heat exchange between the compressed air A2 compressed in the compressor 11 and the air coolant AC taken in from the outside. That is, the first heat exchanger 132 cools the compressed air A2 by the air coolant AC which is at normal temperature. Further, the second heat exchanger 133 performs heat exchange between the heated air AH heated to a high temperature by cooling the compressed air A2, and the fuel gas L. That is, the air coolant AC becomes the high-temperature heated air AH by cooling the compressed air A2, and the second heat exchanger 133 heats the fuel gas L by the heated air AH.

Hereinafter, the second heat exchanger as a heat exchanger of the fifth embodiment will be described. FIG. 13 is a schematic configuration diagram of the heat exchanger of the fifth embodiment.

The second heat exchanger 133 of the fifth embodiment has the fuel gas supply line 24 as a primary flow path, the air coolant line 28 as a secondary flow path, first and second heat exchange units 141 and 142 as a plurality of (in this embodiment, two) heat exchange units, a bypass flow path 143, a flow rate-adjusting valve 144, a temperature sensor 145, and a control unit 146, as shown in FIG. 13. Here, a primary fluid is the fuel gas L, and a secondary fluid is the heated air AH.

The first heat exchange unit 141 and the second heat exchange unit 142 are provided in the fuel gas supply line 24, perform heat exchange between the fuel gas L and the heated air AH, are connected in series, and are disposed in parallel to each other. An inlet header 151 is provided at one end portion of the first heat exchange unit 141, and an upstream-side end portion of the fuel gas supply line 24 is connected to a nozzle 152 of the inlet header 151. An outlet header 153 is provided at one end portion of the second heat exchange unit 142, and a downstream-side end portion of the fuel gas supply line 24 is connected to a nozzle 154 of the outlet header 153. Further, the other end portion of the first heat exchange unit 141 and the other end portion of the second heat exchange unit 142 are connected by a connection header 155. Further, each of the first heat exchange unit 141 and the second heat exchange unit 142 is configured with a heat exchanger tube group composed of a large number of heat exchanger tubes, and an end portion of each heat exchanger tube is supported on tube plates of the headers 151, 153 and 155.

The bypass flow path 143 bypasses the first heat exchange unit 141 out of the first heat exchange unit 141 and the second heat exchange unit 142. A base end portion of the bypass flow path 143 is connected to the fuel gas supply line 24 further on the upstream side than the first heat exchange unit 141, and a leading end portion is connected to a nozzle 156 of the connection header 155. The flow rate-adjusting valve 144 is provided in the bypass flow path 143 and adjusts the flow rate of the fuel gas L flowing through the bypass flow path 143.

The temperature sensor 145 is provided in the fuel gas supply line 24 in the outlet side of the second heat exchange unit 142, measures the temperature of the fuel gas L, and outputs the measurement result to the control unit 146. The control unit 146 adjusts the degree of opening of the flow rate-adjusting valve 144 according to the temperature of the fuel gas L measured by the temperature sensor 145. The control unit 146 adjusts the degree of opening of the flow rate-adjusting valve 144 such that the temperature of the fuel gas L falls into a predetermined temperature range set in advance. That is, the control unit 146 increases the degree of opening of the flow rate-adjusting valve 144 if the temperature of the fuel gas L becomes higher than the predetermined temperature range, and reduces the degree of opening of the flow rate-adjusting valve 144 if the temperature of the fuel gas L becomes lower than the predetermined temperature range.

The second heat exchanger 133 is usually operated with the degree of opening of the flow rate-adjusting valve 144 as 0 (fully closed). The fuel gas L flows through the fuel gas supply line 24, is supplied to and flows through the first heat exchange unit 141, and is then supplied to and flows through the second heat exchange unit 142 through the connection header 155. Further, the fuel gas L is heated by heat exchange with the heated air AH and then discharged.

The control unit 146 adjusts the degree of opening of the flow rate-adjusting valve 144 such that the temperature of the fuel gas L falls into the predetermined temperature range. For example, if the temperature of the air coolant AC becomes higher due to a rise in ambient temperature, the temperature of the heated air AH also becomes higher, the amount of heat exchange (a heat absorption amount of the fuel gas L) in the first heat exchange unit 141 and the second heat exchange unit 142 increases, and the temperature of the fuel gas L exceeds the predetermined temperature range. At this time, the control unit 146 increases the degree of opening of the flow rate-adjusting valve 144 if the temperature of the fuel gas L becomes higher than the predetermined temperature range. Then, a part of the fuel gas L flows from the fuel gas supply line 24 to the bypass flow path 143 according to the degree of opening of the flow rate-adjusting valve 144 and is then supplied from the connection header 155 to the second heat exchange unit 142. That is, a part of the fuel gas L bypasses the first heat exchange unit 141 and is directly supplied to the second heat exchange unit 142. For this reason, a low-temperature fuel gas L which has bypassed the first heat exchange unit 141 is mixed with a high-temperature fuel gas L heated in the first heat exchange unit 141 in the connection header 155, and therefore, the temperature of the fuel gas L flowing through the second heat exchange unit 142 is lowered. As a result, the temperature of the fuel gas L discharged from the second heat exchange unit 142 is lowered, thereby falling into the predetermined temperature range.

In addition, the configuration of the second heat exchanger 133 is not limited to the above-described configuration. FIG. 14 is a schematic configuration diagram of a heat exchanger showing a modification example of the fifth embodiment.

As shown in FIG. 14, a second heat exchanger 133A has the fuel gas supply line 24, the air coolant line 28, the first heat exchange unit 141, the second heat exchange unit 142, the bypass flow path 143, a flow rate-adjusting valve 147, the temperature sensor 145, and the control unit 146.

The bypass flow path 143 bypasses the first heat exchange unit 141, and a base end portion thereof is connected to the fuel gas supply line 24 further on the upstream side than the first heat exchange unit 141, and a leading end portion is connected to the nozzle 156 of the connection header 155. The flow rate-adjusting valve 147 is a three-way valve which is provided in a branch section between the fuel gas supply line 24 and the bypass flow path 143. The degree of opening on the first heat exchange unit 141 side and the degree of opening on the bypass flow path side of the flow rate-adjusting valve (the three-way valve) 147 are adjusted with respect to the fuel gas supply line 24, whereby the flow rate of the fuel gas L flowing to the bypass flow path 143 side is adjusted.

Here, the operations of the second heat exchangers 133 and 133A will be described in comparison with a heat exchange device of the related art. FIG. 15 is a schematic diagram showing the operation of the heat exchanger of the related art, and FIG. 16 is a schematic diagram showing the operation of the heat exchanger of the fifth embodiment.

As shown in FIG. 15, a heat exchanger 001 of the related art is provided in a fuel gas supply flow path 002, a bypass flow path 003 which bypasses the heat exchanger 001 with respect to the fuel gas supply flow path 002 is provided, and a flow rate-adjusting valve 004 is provided in the bypass flow path 003. If the flow rate-adjusting valve 004 is opened by a predetermined degree of opening, fuel gas flows from the fuel gas supply flow path 002 into the heat exchanger 001 at a position t1, thereby being heated, whereby the temperature thereof rises. On the other hand, a part of the fuel gas which has flowed into the bypass flow path 003 is not heated, and thus there is no temperature rising. Then, at a position t2, the fuel gas is discharged from the heat exchanger 001, and at a position t3, high-temperature fuel gas and low-temperature fuel gas which has passed through the bypass flow path 003 are mixed with each other, whereby a temperature is lowered, thereby reaching a predetermined temperature. In the related art, the flow rate of the fuel gas flowing to the heat exchanger 001 is reduced, and therefore, a thermal load of the fuel gas increases, whereby the temperature of the fuel gas exceeds an upper limit temperature to at an outlet of the heat exchanger 001.

On the other hand, as shown in FIG. 16, the second heat exchanger 133 of this embodiment has the first heat exchange unit 141 and the second heat exchange unit 142, and the bypass flow path 143 is connected to a connection section between the first heat exchange unit 141 and the second heat exchange unit 142. For this reason, if the flow rate-adjusting valve 144 is opened by a predetermined degree of opening, the fuel gas flows from the fuel gas supply path 143 into the first heat exchange unit 141 at a position t1, thereby being heated, whereby the temperature thereof rises. On the other hand, a part of the fuel gas which has flowed into the bypass flow path 143 is not heated, and thus there is no temperature rising. Then, at a position t2, the heated fuel gas flows from the first heat exchange unit 141 to the second heat exchange unit 142, and low-temperature fuel gas which has passed through the bypass flow path 143 flows to the second heat exchange unit 142. Here, high-temperature fuel gas and the low-temperature fuel gas are mixed with each other, whereby the temperature of the former is lowered. Thereafter, all of the fuel gas is heated in the second heat exchange unit 142, whereby the temperature thereof rises, and at a position t3, the temperature reaches a predetermined temperature. In this embodiment, the low-temperature fuel gas returns to the connection section between the heat exchange units 141 and 142, and therefore, the temperature of the fuel gas is prevented from exceeding an upper limit temperature to at an outlet of the second heat exchanger 133.

In this manner, the heat exchanger of the fifth embodiment is provided with the fuel gas supply line 24 through which the fuel gas L as a primary fluid flows, the air coolant line 28 through which the heated air AH as a secondary fluid flows, the first and second heat exchange units 141 and 142 which perform heat exchange between the fuel gas L and the heated air AH, the bypass flow path 143 which bypasses the first heat exchange unit 141, the flow rate-adjusting valve 144 which adjusts the flow rate of the fuel gas L flowing through the bypass flow path 143, the temperature sensor 145 which measures the temperature of the fuel gas L in the outlet side of the heat exchange unit 142, and the control unit 146 which adjusts the degree of opening of the flow rate-adjusting valve 144 according to the temperature of the fuel gas L detected by the temperature sensor 145.

Therefore, the degree of opening of the flow rate-adjusting valve 144 is adjusted according to the temperature of the fuel gas L in the outlet side of the second heat exchange unit 142, and therefore, the flow rate of the fuel gas L which bypasses the first heat exchange unit 141 is adjusted. At this time, a part of the fuel gas L bypasses only the first heat exchange unit 141, and therefore, even if the flow rate of the fuel gas L passing through the first heat exchange unit 141 is temporarily reduced, an extreme increase in temperature is suppressed. As a result, in the heat exchanger of the fifth embodiment, it is possible to adjust the temperature of the fuel gas L with a high degree of accuracy and it is possible to suppress overheating of the fuel gas L.

Further, overheating of the fuel gas L is suppressed, whereby a large thermal load does not act on constituent members (for example, heat exchanger tubes or the like) of the heat exchange unit 142, and an increase in plate thickness, or the like is not required, and thus it is possible to suppress an increase in manufacturing cost. Further, overheating of the fuel gas L is suppressed, and therefore, a by-product (for example, iron sulfide: FeS) is not produced, and thus it is possible to prevent an adverse effect of the by-product on the heat exchangers 133 and 133A.

In the heat exchanger of the fifth embodiment, the first heat exchange unit 141 and the second heat exchange unit 142 are connected in series, one end portion of the bypass flow path 143 is connected to the inlet side of the first heat exchange unit 141, and the other end portion is connected to the connection header 155 between the first heat exchange unit 141 and the second heat exchange unit 142. Therefore, the fuel gas L passing through the bypass flow path 143 is supplied to the connection header 155, whereby the fuel gas L heated in the first heat exchange unit 141 and the low-temperature fuel gas L which has passed through the bypass flow path 143 are mixed with each other, and thus a rise to a higher temperature of the fuel gas L in the second heat exchange unit 142 is suppressed, whereby overheating of the fuel gas L can be suppressed.

In the heat exchanger of the fifth embodiment, the first heat exchange unit 141 and the second heat exchange unit 142 are disposed in parallel, the inlet header 151 of the first heat exchange unit 141 and the outlet header 153 of the second heat exchange unit 142 are disposed at one end portion, and the connection header 155 is disposed at the other end portion. Therefore, due to a configuration made so as to efficiently circulate the fuel gas L by disposing the first heat exchange unit 141 and the second heat exchange unit 142 in parallel, it is possible to attain a reduction in the size of the device.

In the heat exchanger of the fifth embodiment, a downstream-side end portion in the first heat exchange unit 141 and an upstream-side end portion in the second heat exchange unit 142 are connected by the connection header 155. Therefore, a connection section is made to be the connection header 155, whereby it is possible to easily connect the first heat exchange unit 141 and the second heat exchange unit 142, and it is possible to suitably mix the fuel gas L which has passed through the heat exchange unit 141 and the fuel gas L which has passed through the bypass flow path 143.

In the heat exchanger of the fifth embodiment, the flow rate-adjusting valve 144 is provided in the bypass flow path 143. Therefore, it is possible to simplify the structure and it is possible to reduce the manufacturing cost.

In the heat exchanger of the fifth embodiment, the flow rate-adjusting valve 147 is made to be the three-way valve which is provided in the branch section between the fuel gas supply line 24 and the bypass flow path 143. Therefore, the flow rate of the fuel gas L flowing to the bypass flow path 143 can be adjusted with a high degree of accuracy.

Sixth Embodiment

FIG. 17 is a schematic configuration diagram of a heat exchanger of a sixth embodiment, and FIG. 18 is a schematic configuration diagram of a heat exchanger showing a modification example of the sixth embodiment. In addition, members having the same functions as those in the above-described embodiments are denoted by the same reference numerals and detailed description thereof is omitted.

In the sixth embodiment, as shown in FIG. 17, a second heat exchanger 133B has the fuel gas supply line 24, the air coolant line 28, the first heat exchange unit 141, the second heat exchange unit 142, the bypass flow path 143, the flow rate-adjusting valve 144, the temperature sensor 145, and the control unit 146.

The first heat exchange unit 141 and the second heat exchange unit 142 are provided in the fuel gas supply line 24, perform heat exchange between the fuel gas L and the heated air AH, are connected in series, and are disposed in parallel to each other. The inlet header 151 is provided at one end portion of the first heat exchange unit 141, and an upstream-side end portion of the fuel gas supply line 24 is connected to the nozzle 152 of the inlet header 151. The outlet header 153 is provided at one end portion of the second heat exchange unit 142, and a downstream-side end portion of the fuel gas supply line 24 is connected to the nozzle 154 of the outlet header 153. Further, an outlet header 157 is provided at the other end portion of the first heat exchange unit 141, and an inlet header 158 is provided at the other end portion of the second heat exchange unit 142. Further, the outlet header 157 of the first heat exchange unit 141 and the inlet header 158 of the second heat exchange unit 142 are connected by a connection pipe 159 as a connection section.

The bypass flow path 143 bypasses one heat exchange unit 141 among the plurality of heat exchange units 141 and 142. A base end portion of the bypass flow path 143 is connected to the fuel gas supply line 24 further on the upstream side than the first heat exchange unit 141, and a leading end portion is connected to the connection pipe 159. The flow rate-adjusting valve 144 is provided in the bypass flow path 143 and adjusts the flow rate of the fuel gas L flowing through the bypass flow path 143.

The temperature sensor 145 is provided in the fuel gas supply line 24 in the outlet side of the second heat exchange unit 142, measures the temperature of the fuel gas L, and outputs the measurement result to the control unit 146. The control unit 146 adjusts the degree of opening of the flow rate-adjusting valve 144 according to the temperature of the fuel gas L measured by the temperature sensor 145. The control unit 146 adjusts the degree of opening of the flow rate-adjusting valve 144 such that the temperature of the fuel gas L falls into a predetermined temperature range set in advance.

The configuration of the second heat exchanger 133B is not limited to the above-described configuration. As shown in FIG. 18, a second heat exchanger 133C has the fuel gas supply line 24, the air coolant line 28, the first heat exchange unit 141, the second heat exchange unit 142, the bypass flow path 143, the flow rate-adjusting valve 147, the temperature sensor 145, and the control unit 146.

The bypass flow path 143 bypasses the first heat exchange unit 141, and a base end portion thereof is connected to the fuel gas supply line 24 further on the upstream side than the first heat exchange unit 141, and a leading end portion is connected to the connection pipe 159. The flow rate-adjusting valve 147 is a three-way valve which is provided in the branch section between the fuel gas supply line 24 and the bypass flow path 143. The degree of opening on the first heat exchange unit 141 side and the degree of opening on the bypass flow path 143 side of the flow rate-adjusting valve (the three-way valve) 147 are adjusted with respect to the fuel gas supply line 24, whereby the flow rate of the fuel gas L flowing to the bypass flow path 143 side is adjusted.

Further, the operations of the second heat exchangers 133B and 133C are substantially the same as those in the fifth embodiment described above, and therefore, description thereof is omitted here.

In this manner, in the heat exchanger of the sixth embodiment, the outlet header 157 of the first heat exchange unit 141 and the inlet header 158 of the second heat exchange unit 142 are connected by the connection pipe 159 as a connection section. Therefore, the connection section is made to be the connection pipe 159, whereby it is possible to compactly connect the first heat exchange unit 141 and the second heat exchange unit 142, and thus it is possible to simplify the structure.

Seventh Embodiment

FIG. 19 is a schematic configuration diagram of a heat exchanger of a seventh embodiment. In addition, members having the same functions as those in the above-described embodiments are denoted by the same reference numerals and detailed description thereof is omitted.

In the seventh embodiment, as shown in FIG. 19, a second heat exchanger 160 has the fuel gas supply line 24, the air coolant line 28, a first heat exchange unit 161, a second heat exchange unit 162, a third heat exchange unit 163, a bypass flow paths 164 and 165, flow rate-adjusting valves 166 and 167, a temperature sensor 168, and a control unit 169.

The heat exchange units 161, 162 and 163 are provided in the fuel gas supply line 24, perform heat exchange between the fuel gas L and the heated air AH, are connected in series, and are disposed in parallel to each other. An inlet header 171 is provided at one end portion of the first heat exchange unit 161, and an upstream-side end portion of the fuel gas supply line 24 is connected to a nozzle 172 of the inlet header 171. Further, an outlet header 173 is provided at the other end portion of the first heat exchange unit 161. An inlet header 174 is provided at the other end portion of the second heat exchange unit 162 and an outlet header 175 is provided at one end portion. An inlet header 176 is provided at one end portion of the third heat exchange unit 163, an outlet header 177 is provided at the other end portion, and a downstream-side end portion of the fuel gas supply line 24 is connected to a nozzle 178 of the outlet header 177.

Further, the outlet header 173 of the first heat exchange unit 161 and the inlet header 174 of the second heat exchange unit 162 are connected by a connection pipe 179. Further, the outlet header 175 of the second heat exchange unit 162 and the inlet header 176 of the third heat exchange unit 163 are connected by a connection pipe 180.

The first bypass flow path 164 bypasses the first heat exchange unit 161, and the second bypass flow path 165 bypasses the first heat exchange unit 161 and the second heat exchange unit 162. A base end portion of the first bypass flow path 164 is connected to the fuel gas supply line 24 further on the upstream side than the first heat exchange unit 161 and a leading end portion is connected to the connection pipe 179. A base end portion of the second bypass flow path 165 is connected to the fuel gas supply line 24 further on the upstream side than the first heat exchange unit 161 and a leading end portion is connected to the connection pipe 180. The first flow rate-adjusting valve 166 is provided in the first bypass flow path 164 and adjusts the flow rate of the fuel gas L flowing through the first bypass flow path 164. The second flow rate-adjusting valve 167 is provided in the second bypass flow path 165 and adjusts the flow rate of the fuel gas L flowing through the second bypass flow path 165.

The temperature sensor 168 is provided in the fuel gas supply line 24 in the outlet side of the third heat exchange unit 163, measures the temperature of the fuel gas L, and outputs the measurement result to the control unit 169. The control unit 169 adjusts the degrees of opening of the flow rate-adjusting valves 166 and 167 according to the temperature of the fuel gas L measured by the temperature sensor 168. The control unit 169 adjusts the degrees of opening of the flow rate-adjusting valves 166 and 167 such that the temperature of the fuel gas L falls into a predetermined temperature range set in advance. That is, the control unit 169 increases the degrees of opening of the flow rate-adjusting valves 166 and 167 if the temperature of the fuel gas L becomes higher than the predetermined temperature range, and reduces the degrees of opening of the flow rate-adjusting valves 166 and 167 if the temperature of the fuel gas L becomes lower than the predetermined temperature range.

The second heat exchanger 160 is usually operated with the degrees of opening of the flow rate-adjusting valves 166 and 167 as 0 (fully closed). The fuel gas L flows through the fuel gas supply line 24, and when the fuel gas L flows through the respective heat exchange units 161, 162 and 163, the fuel gas L is heated by heat exchange with the heated air AH.

The control unit 169 adjusts the degrees of opening of the flow rate-adjusting valves 166 and 167 such that the temperature of the fuel gas L falls into a predetermined temperature range. For example, if the temperature of the air coolant AC becomes higher due to a rise in ambient temperature, the temperature of the heated air AH also becomes higher, the amount of heat exchange (a heat absorption amount of the fuel gas L) in the respective heat exchange units 161, 162 and 163 increases, and the temperature of the fuel gas L exceeds the predetermined temperature range. At this time, the control unit 169 first increases the degree of opening of the second flow rate-adjusting valve 167 if the temperature of the fuel gas L becomes higher than the predetermined temperature range. Then, a part of the fuel gas L is supplied from the fuel gas supply line 24 to the third heat exchange unit 163 through the bypass flow path 165 according to the degree of opening of the second flow rate-adjusting valve 167. That is, a part of the fuel gas L bypasses the first heat exchange unit 161 and the second heat exchange unit 162 and is directly supplied to the third heat exchange unit 163. For this reason, low-temperature fuel gas L which has bypassed the first heat exchange unit 161 and the second heat exchange unit 162 is mixed with high-temperature fuel gas L heated in the first heat exchange unit 161 and the second heat exchange unit 162 in the connection pipe 180, and therefore, the temperature of the fuel gas L flowing through the third heat exchange unit 163 is lowered. As a result, the temperature of the fuel gas L discharged from the third heat exchange unit 163 is lowered, thereby becoming lower than the predetermined temperature range.

Further, the control unit 169 next increases the degree of opening of the first flow rate-adjusting valve 166 if the temperature of the fuel gas L is not sufficiently lowered even if the degree of opening of the second flow rate-adjusting valve 167 is increased. At this time, the second flow rate-adjusting valve 167 may be closed. Then, a part of the fuel gas L is supplied from the fuel gas supply line 24 to the second heat exchange unit 162 through the bypass flow path 164 according to the degree of opening of the first flow rate-adjusting valve 166. That is, a part of the fuel gas L bypasses the first heat exchange unit 161 and is directly supplied to the second heat exchange unit 162. For this reason, low-temperature fuel gas L which has bypassed the first heat exchange unit 161 is mixed with high-temperature fuel gas L heated in the first heat exchange unit 161 in the connection pipe 179, and therefore, the temperature of the fuel gas L flowing through the second heat exchange unit 162 is lowered. As a result, the temperature of the fuel gas L discharged from the second heat exchange unit 162 is lowered, thereby falling into the predetermined temperature range.

In this manner, the heat exchanger of the seventh embodiment is provided with the fuel gas supply line 24, the air coolant line 28, the respective heat exchange units 161, 162 and 163 which perform heat exchange between the fuel gas L and the heated air AH, the first bypass flow path 164 which bypasses the first heat exchange unit 161, the second bypass flow path 165 which bypasses the first heat exchange unit 161 and the second heat exchange unit 162, the flow rate-adjusting valves 166 and 167 which adjust the flow rate of the fuel gas L flowing through the bypass flow paths 164 and 165, the temperature sensor 168 which measures the temperature of the fuel gas L in the outlet side of the third heat exchange unit 163, and the control unit 169 which adjusts the degrees of opening of the flow rate-adjusting valves 166 and 167 according to the temperature of the fuel gas L detected by the temperature sensor 168.

Therefore, the degrees of opening of the flow rate-adjusting valves 166 and 167 are adjusted according to the temperature of the fuel gas L in the outlet side of the third heat exchange unit 163 disposed on the side furthest downstream, and therefore, the flow rate of the fuel gas L which bypasses the respective heat exchange units 161 and 162 is adjusted. At this time, a part of the fuel gas L bypasses only the first heat exchange unit 161, or the respective heat exchange units 161 and 162, and therefore, even if the flow rate of the fuel gas L passing through the respective heat exchange units 162 and 163 or the third heat exchange unit 163 is temporarily reduced, an extreme increase in temperature is suppressed. As a result, in the heat exchanger of the seventh embodiment, it is possible to adjust the temperature of the fuel gas L with a high degree of accuracy and it is possible to suppress overheating of the fuel gas L.

In addition, in the embodiments described above, the two heat exchange units 141 and 142 or the three heat exchange units 161, 162 and 163 are provided. However, it is favorable if the number of heat exchange units is a plurality, and three or more heat exchange units may be provided. Further, at this time, a configuration is made such that the bypass flow paths 143 and 164 bypass the first heat exchange unit 141 or 161 and the bypass flow path 165 bypasses the first and second heat exchange units 161 and 162. However, there is no limitation to this configuration. For example, the bypass flow path may bypass only the second heat exchange unit 162 or may bypass only the third heat exchange unit 163.

Further, in the embodiments described above, each of the heat exchange units 141, 142, 161, 162, and 163 is configured with a heat exchanger tube which is a straight tube. However, each heat exchange unit may be configured with a U-shaped heat exchanger tube.

Further, in the embodiments described above, the heat exchanger according to the present invention is applied to the gas turbine 10 and heats the fuel gas (the primary fluid) L by the heated air (the secondary fluid) AH. However, there is no limitation to this configuration. That is, the heat exchanger according to the present invention can also be applied to another part in the gas turbine 10, or fields (for example, a boiler or the like) other than the gas turbine 10.

Further, in the embodiments described above, the heat exchanger which heats the primary fluid by the secondary fluid is adopted. However, a heat exchanger which cools the primary fluid by the secondary fluid may be adopted, and in this case, it is possible to suppress supercooling due to the heat exchanger.

REFERENCE SIGNS LIST

-   -   10: gas turbine     -   11: compressor     -   12: combustor     -   13: turbine     -   14: power generator     -   24: fuel gas supply line     -   26: heat exchange device     -   27: compressed air branching line (primary flow path)     -   28: air coolant line (secondary flow path)     -   32, 32A, 32B, 32C, 32D, 32E, 90: first heat exchanger     -   33: second heat exchanger (heat exchanger)     -   41, 91: first heat exchange unit     -   42, 92: second heat exchange unit     -   43, 95, 96, 97. 98: flow rate-adjusting valve     -   71, 72: temperature sensor (state detection sensor)     -   73, 100: control unit     -   81, 99: flow rate sensor (state detection sensor)     -   AC: air coolant (secondary fluid)     -   A2: compressed air (primary fluid)     -   132: first heat exchanger     -   133, 133A, 133B, 133C, 160: second heat exchanger (heat         exchanger)     -   141, 161: first heat exchange unit     -   142, 162: second heat exchange unit     -   143, 164, 165: bypass flow path     -   144, 166, 167: flow rate-adjusting valve     -   145, 168: temperature sensor     -   146, 169: control unit     -   151, 158, 171, 174, 176: inlet header     -   153, 157, 173, 175, 177: outlet header     -   155: connection header (connection section)     -   159: connection pipe (connection section)     -   163: third heat exchange unit     -   AC: air coolant     -   AH: heated air (secondary fluid)     -   L: fuel gas (primary fluid) 

1-15. (canceled)
 16. A heat exchanger comprising: a primary flow path through which a primary fluid flows; a secondary flow path through which a secondary fluid flows within the primary flow path; a plurality of heat exchange units which perform heat exchange between the primary fluid and the secondary fluid and are provided side by side in a flow direction of the secondary fluid; and a flow rate-adjusting valve which adjusts a flow rate of the primary fluid flowing to the plurality of heat exchange units, wherein the plurality of heat exchange units have a shared inlet header provided at one end portion and an individual outlet header provided at the other end portion, the primary flow path is connected to the inlet header and the outlet header, and the flow rate-adjusting valve is provided in the primary flow path which is connected to the outlet header.
 17. A heat exchanger comprising: a primary flow path through which a primary fluid flows; a secondary flow path through which a secondary fluid flows within the primary flow path; a plurality of heat exchange units which perform heat exchange between the primary fluid and the secondary fluid and are provided side by side in a flow direction of the secondary fluid; a flow rate-adjusting valve which adjusts a flow rate of the primary fluid flowing to the plurality of heat exchange units which are provided in the primary flow path which is connected to the heat exchange unit which is disposed on the side furthest downstream in a flow direction of the secondary fluid; a state detection sensor which detects a state of the primary fluid; and a control unit which adjusts a degree of opening of the flow rate-adjusting valve according to the state of the primary fluid detected by the state detection sensor.
 18. The heat exchanger according to claim 16, wherein the plurality of heat exchange units have an individual inlet header provided at one end portion and a shared outlet header provided at the other end portion, the primary flow path is connected to the inlet header and the outlet header, and the flow rate-adjusting valve is provided in the primary flow path which is connected to the inlet header.
 19. The heat exchanger according to claim 16, wherein the state detection sensor is a temperature sensor which detects a temperature of the primary fluid in the side of outlets of the plurality of heat exchange units, and the control unit reduces the degree of opening of the flow rate-adjusting valve when a difference in temperature of the primary fluid in the side of outlets of the plurality of heat exchange units has become larger than a predetermined temperature difference set in advance.
 20. The heat exchanger according to claim 16, wherein the state detection sensor is a flow rate sensor which detects a flow rate of the primary fluid in the side of inlets of the plurality of heat exchange units, and the control unit reduces the degree of opening of the flow rate-adjusting valve when the flow rate of the primary fluid in the side of inlets of the plurality of heat exchange units has become smaller than a predetermined flow rate set in advance.
 21. The heat exchanger according to claim 16, wherein the state detection sensor is a pressure sensor which detects a pressure of the primary fluid in the side of inlets of the plurality of heat exchange units, and the control unit reduces the degree of opening of the flow rate-adjusting valve when the pressure of the primary fluid in the side of inlets of the plurality of heat exchange units has become larger than a predetermined pressure set in advance.
 22. A heat exchanger comprising: a primary flow path through which a primary fluid flows; a secondary flow path through which a secondary fluid flows within the primary flow path; a plurality of heat exchange units which perform heat exchange between the primary fluid and the secondary fluid; a bypass flow path which bypasses at least one heat exchange unit among the plurality of heat exchange units; a flow rate-adjusting valve which adjusts a flow rate of the primary fluid flowing through the bypass flow path; a temperature sensor which measures a temperature of the primary fluid in the side of outlets of the plurality of heat exchange units; and a control unit which adjusts a degree of opening of the flow rate-adjusting valve according to the temperature of the primary fluid detected by the temperature sensor.
 23. The heat exchanger according to claim 22, wherein the plurality of heat exchange units have a first heat exchange unit and a second heat exchange unit connected in series, and the bypass flow path is connected, at one end portion, to an inlet of the first heat exchange unit and connected, at the other end portion, to a connection section between the first heat exchange unit and the second heat exchange unit.
 24. The heat exchanger according to claim 23, wherein the first heat exchange unit and the second heat exchange unit are disposed in parallel, an inlet portion of the first heat exchange unit and an outlet portion of the second heat exchange unit are disposed at one end portion, and the connection section is disposed at the other end portion.
 25. The heat exchanger according to claim 23, wherein the connection section is a header to which a downstream-side end portion in the first heat exchange unit and an upstream-side end portion in the second heat exchange unit are connected.
 26. The heat exchanger according to claim 23, wherein the connection section is a connection pipe which connects a downstream-side end portion in the first heat exchange unit to an upstream-side end portion in the second heat exchange unit.
 27. The heat exchanger according to claim 22, wherein the flow rate-adjusting valve is provided in the bypass flow path.
 28. The heat exchanger according to claim 22, wherein the flow rate-adjusting valve is a three-way valve which is provided in a branch section between the primary flow path and the bypass flow path. 